Gas-engine



W. E. GRIST.

GAS ENGINE.

(No Model.)

Patented Dec 17; 1889.

ll ll L W h i HIE a lll ll ll\lll| UNITED STATE PATENT OFFICE.

IVILLIAM E. CRIST, OF BROOKLYN, NEIV YORK.

GAS-ENGINE.

SPECIFICATION forming part of Letters Patent No. 417,471, dated December17, 1889,

Application filed m 10, 1889. Serial N0. 317,039. (no model.)

To all whom it may concern.-

Be it known that I, VVILLIAM E. CRIST, of Brooklyn, in the county ofKings and State of New York, have invented certain new and usefulImprovements in Gas-Engines; and I do hereby declare that the followingis afull and exact description thereof, reference being had to theaccompanying drawings, and to the letters of reference marked thereon,making a part of this specification.

This invention pertains to that class of motors which are driven by theexplosion of a gas or gaseous compound, and relates to the improvedconstruction of an engine of this type having vibrating pistons.

It consists in the improved construction, combination, and arrangementof its several parts, as hereinafter described and claimed, whereby theworking chambers are exposed tot'he air for cooling, the burned gasesare freely exhausted from before the pistons, and a fresh charge iscompressed and exploded under each at the end of every stroke.

In the accompanying drawings, Figure 1 is an end View of my improvedvibrating gasengine, showing one-half thereof in central section; and.Fig. 2, a side View showing likewise one-half thereof in centralsection.

Similar letters indicate like parts in both of the figures. 1

A represents a cylindrical segmental casing formed integrally with orsecured upon a suitable base B, parallel with its axis. A portion of thecasing embracing an arc of about ninety degrees (more or less) is whollyremoved from the side thereof opposite the base. Its ends are closed byend plates or heads 0 C, securely bolted thereto. These heads furnishbearings for a shaft D, extending longitudinally through the casing incoincidence with its axis. This shaft is mounted to rock in itsbearings, and is fitted with two radial plates D and D which extend theentire length of the inside of the casing, so as to make a close jointwith the inner face of each of its-heads and project out from the shaftin opposite directions far enough to contact at their outer edges withthe inner periphery of the casing.

arepreferably formed in'the same diametric plane and in one piece withthe axial shaft These radial plates- D, and in combination therewithconstitute the oscillating pistons of the engine. The joints between thewalls of the casing and the pistons are packed by means of metallicspring-seated packin -strips a a, inserted in longitudinal grooves inthe ends and edges of each piston to bear outwardly in thecustomarymanner against the walls.

A crank-shaft E is mounted above the easing A parallel with thepiston-shaft D, in suitable bearings in the two heads 0 O, which areextended far enough for the purpose, and

a crank formed in the shaft E, preferably midway the length of thecasing, by means of two disks E E, and a transverse pin 7 (see Fig. 2)is coupled by a connecting-rod E to one of the piston-plates D; hencethe oscillation of the piston is made to produce a rotation of thecrank-shaft, and the crank is so proportioned with reference to theradial distance of the connection of the rod E with the piston fromthe'axis of the piston that a revolution of the crank is produced ateach oscillation of the piston over an arc of about ninety degrees, moreor less.

The inner portion of the casing is divided longitudinally bypartition-walls F F, which extend from end toend thereof and radiatefrom theinner side of the piston-shaft D to the inner periphery of thecasing at a diverdegrees, and the pistons are so adjusted in theirconnection to the crank E that when the inner face of either piston isbrought up closely against the proximate partition-wall F the crank willbe on a dead-center. In the movement of the engine the crank E is carried past its dead-center in the customary manner by the momentum of afiy-wheel E fixed upon the crank-shaft E.

The piston-shaft D is confined and supported throughout its lengthwithin the casing between the apex of the diverging partition-walls F Fon one side and the edge of a parallel bar F, mounted on thediametrically-opposite side thereof, and Whose ends are fixed in theends of the'casing. This bar F serves also to strengthen the casing, andto prevent the hot air discharged from the into the other. The jointsbetween the shaft and said longitudinal supports are severally packed bymeans of spring-seated packingstrips a, or other equivalent paeki n gmaterial, fitted in longitudinal groovesin the partition and thesupporting-bar.

The segmental space included within the casing next to the base P,between the radially-diverging partition-walls F F and the innerperiphery and ends of the casing, eonstitutes the supply-chamber I l ofthe engine. A vibrating piston G is mounted in said chamber, being madeto project therein from a rocksha-ft G, fitted in the inner centralangle of the chamber and made to oscillate in suitable bearings formedin the heads 0 C of the easing. The edges of this piston are packed tomaintain a close joint with the inner walls of the supply-chamber asthey move over it, and the rock-shaft G is also packed in itslongitudinal seat, so as to prevent a leakage from the one side to theother.

The two outer corners or angles of the supply-chamber II are made tocommunicate, each by means of an extended port ll',with a cylindricalvalve-chamber I, formed within the base B to extend from end to endthereof, within which is fitted closely a cylindrical tubularvalve-piece J. This valve-piece J is formed with a longitudinalpartition or septum therein extending from end to end thereof, dividingit into two unequal chambers, the larger of which is left open and thesmaller closed at each end. The longitudinal septum is longitudinallyslotted to form a narrow slit or valve-opening c, communicating with thelarger open-ended chamber for a length about equal to that of the portII. This valve-opening is closed automatically by a weighted orspring-actuated flap-valve K, fitted in the smaller closed chamber andhinged at one edge to the face of the septum to extend over and closeupon the valve-opening c. A second longitudinal cylindrical passage orbore (1 is provided in the valve-piece J under the hinge of the valve K,and a small narrow longitudinal slot (2 is pierced intermediate thevalve-opening c and the hinge of the valve K to communicate with saidcylindrical passage and be covered and closed by the valve. Thecylindrical passage or bore (1 is closed at one end and connected at theother with a gas-supply pipe d, so that while a supply of air will beadmitted to the port H through the open ends of the enlarged chamberunder the valve K when the valve is lifted a supply of gas will besimultaneously admitted through the bore (Z. An inner tube d may befitted within the bore (1 to admit of rotation therein and belongitudinally perforated to serve as a valve to control the slot 2, andthereby regulate the delivery of gas through the same as theperforations are brought into more or less com plete registry with theslot by a rotation of the tube (1 This rotation may be effected by meansof a governor attached to the engine.

By withdrawing the valve-piece J from its seat in the valve-chamber Ithe valve K may be readily reached for repair or renewal. The open endsof the valve-piece may be protected by wire screens '1, as shown in Fig.1.

A narrow extended port L is formed centrally through each of thepartition-walls F F to establish communication between thesupply-chamber and the piston-chambers, and each port is covered by asuitable springaet-uated puppet-valve L adapted thereto, and which isseated in the piston-chamber and is guided by a suitable stem working inthe port. The spring for automatically closing the valve is preferablyfitted within the port L, and may consist of an elastic plate U,attached centrally to the valve-stem, and whose ends shall engage thewalls of the port, the spring-plate being perforated to present theleast possible obstruction to the flow of the gases through the port.

The outer end of the rock-shaft G, carrying the compressing piston G, isfitted with a crank-arm G which is coupled bya connectin g-rod G to awrist-pin S upon the fiy-wheel E on the crank-shaft E, so that therevolution of said shaft shall produce an oscillation of thecompressing-piston G in synehronism with the movements of thedriving-pistons D D The wrist-pin S is so adjusted with reference to thecrank-arm G and to the crank E, coupled to the driving-piston, that thecompressing-piston G shall invariably move in the direction opposite tothat of the working-piston, which is being driven by the force of anexplosion. This movement of the compressing-piston will operate to drawin behind it into the supply-chamber through one of the induction-portsII a supply of air or gas and to compress the admixed air and gas infront of it, constituting the explosive charge, toward thedriving-piston which is moving toward it in the working-chamber. Theexplosive charge is retained in the supply-chamber by the resistance ofthe spring actuating the valve L until the approaching driving-piston inthe piston-chamber has completed its stroke toward the valve and hascommenced its return, the burned gases in front of said drivingpistonbeing in the meanwhile freely discharged as it advances through anexhaustport Q in the casing A, opening outwardly from the inner outerangle of each pistonchamber.

Each exhanst-port Q is controlled, as shown in Fig. 1, by a valve M,carried upon an arm projecting from a rock-shaft M, which is positivelyoperated in synehronism with the movement of the compressing-piston G bymeans of a crank-arm M on its outer end, coupled by a connecting-rod Nwith a corresponding crank-arm N on the end of the shaft G, carryingsaid piston, said arms being so adjusted with reference to thecompressing-piston G, and allowed to have so much lost motion each bymeans of longitudinal slot Y therein, as that each exhaust-valve M shallclose just before said piston has completed its stroke and has so farcompressed the explosive charge before it as to force open the valve Lagainst the stress of its spring. After the exhaust-valve has closed, somuch of the burned gas as may still remain in the working-chamber iscompressed and driven into the exhaust-port Q and the space in front ofits valve M, so that, as the driving-piston begins to make itsreturn-stroke, the explosive charge entering through the valve L willalone fill the space under the inner face of.

the piston. At the instant the explosive chargeenters theworking-chamber under the driving-piston it will be exploded by theaction of the igniting-device. This igniting device may be of any of theapproved forms now well known to the art, to be rendered effective bythe use either of a gas-flame or by means of an electric spark.

Practically I have found the ignitor illustrated in the accompanyingdrawings to be an efficient one. Said ignitor consists simply of a tubeP, closed at one end and communieating at the other through the casingwith the inner end of the piston-chamber near to the inlet-valveL'. Thistube is kept at ared heat by means of a Bunsen burner P, or

other suitable means, and so soon as the compressed explosive charge hasentered the piston-chamber a portion of it, entering the tube P, willbecome ignited and produce an explosion of the entire charge. A separateignitor is preferably connected with each of the piston-chambers. As thecompressing-piston begins its return-stroke at the moment it has fullydriven the explosive charge into the working-chamber, the valve L isthereupon at once relieved, and will instantly close.

The piston-chambers are encircled by a water-jacket R, formed within thewalls of the casing in the customary manner, the several water-spacesbeing connected by transverse passages in the heads of the casing,adapted to facilitate a circulation of water in the jacket. Thewater-supply is admitted through inlet-ports R R in the lower part ofeach head, from which it flows and circulates through the several spacesof the waterjacket and is discharged through central outlets R R in theupper part of the casing, on each side thereof. a

As the piston-chambers outside of the pistons are opened freely to theair the currents of air which follow the pistons as they are carriedinward and are expelled again by their outward movement will assistgreatly in cooling the walls of said chambers.

In the operation of this improved motor, by turning the shaft E so thatit shall make one revolution the compressing-piston G will, during thefirst half of said revolution, draw a charge of air, .admixed with a dueproportion of gas, through the inlet-port I-I into the supply-chamber H,and during the remainder of the revolution will, by its return-stroke,compress said charge. In the meantime the neously withthe'compressing-piston in directions opposed thereto, so that as thelatter drives and compresses the charge of admixed air and gas towardeither port L in the supply chamber communicating with eitherWorking-chamber, the piston in said working-- chamber will be carriedtoward the same port. During this movement of the working-piston theexhaust-valve G will be open and will allow a free exhaust of the'air orburned gases from in front of the piston until the stroke of the pistonis nearly completed, whereupon the exhaust-valve will be closed inmanner as described. The remainder of the stroke of the piston will thencompress so much of the air and burned gases as remains out into theexhaust-port Q. As the compressing piston compresses the charge in thesupply-chamber, the spring which governs the valve L, toward which thepiston is moving, will operate to retain and confine the charge in thesupply-chamber against the stress of the 'advancing piston. The power ofthe spring to hold the valve L closed, and thus confine the compressedcharge, will be re-enforced so soon as the exhaust-valve is closed bythe pressure of the air' and gas in the workingchamher upon said valveL, efiected by the advance toward it of the working-piston as itcompletes its stroke. So soon, however, as the piston begins itsreturnstroke so as to diminish this pressure, the valve L, relievedtherefrom, will no longer resist the pressure of the charge, and willfly open against the stress of its spring, and as the compressingpistoncompletes its stroke the charge will be wholly carried into theworking-chamber, and be thereupon instantly ignited and exploded toexert itsfull force against the receding working-piston, which, as thecrank will have then fully passed the dead-center, will be in positionto act most effectively upon the crank. To render this delivery of theexplosive charge into the working chamber prompt and effective, thecompressing-piston is so geared that it will move with its greatestrapidity at the end of its stroke in each direction, occurring after theexhaustvalve has been closed, the driving-piston at the same time makingits slowest movement. So soon as the explosive charge has thus beendischarged into the workingcylinder, the valveL will, under the stressof its spring, automatically close, being relieved from pressure on itsinner side by reason of the return movement of the compressing-piston,which begins at this moment. The exhaust-valve will remain closed duringthe entire out-ward stroke of the piston, but will open so soon as thestroke is reversed, to allow a free vent for the burned gases during thereturninward stroke.

While one piston is moving outward on one ing inward and discharging theburned gases by whose explosion it was carried outward, the movement ofthe compressing-piston operating meantime to compress a fresh charge andto draw in a fresh supply of air and gas in readiness for compression.There is thus virtually a continuous application of power in thisengine, the intermissions, more or less frequent, which occur in otherforms of gasengines being wholly avoided therein.

I claim as my invention- 1. The combination, in a vibrating gas-engine,of acentral rock-shaft, segmental working-chambers formed on oppositesides thereof, oscillating pistons fixed to the shaft to vibrate in saidworking chambers, exhaustvalves communicating with the inner ends ofsaid chambers, means, substantially as described, for opening saidexhaust-valves durin g the instroke and closing the same during theoutstroke of each piston,a single supplychamber for receiving andcompressing the charge for both working-chambers and communicating bysuitable ports at its opposite ends with the inner end of each valvecontrolling said ports and opening toward the working-chambers, acompressing-piston reciprocating in said supply-chamber in unison withthe movements of the working-pistons to deliver a charge of compressedgas into each working-chamber at the end of the instroke of its piston,valves opening in to the opposite ends of the supply-chamber, and meansfor igniting the charge forced into each working-chamber by thecompressing-piston, substantially in the manner and for the purposeherein set forth.

2. The combination, in a gas-engine, of a working-piston reciprocatingin a workingchamber, a compressing-piston moving in a separatesupply-chamber toward the workingpiston as it advances and from it as itrecedes, a valve controlling a port connecting the supply and workingchambers and opening toward the latter, a spring, substantially asdescribed, controlling said valve,a valve controlling an exhaust-portcommunicating with the inner end of the working-chamber, a rock-armcarrying said exhaust-valve and actuated in coincidence with thecompressing piston by connection with its shaft, whereby the valve ismade to open as the working-piston moves inward and close as said pistonmoves outward, and an igniting device communicating with the inner endof the working-chamber, all substantially in the manner and for thepurpose herein set forth.

3. The combination, in a gas-engine, of a central rock-shaft, segmentalworking-chambers formed on opposite sides thereof and provided withexhaust-valves at their inner ends, oscillating pistons fixed to theshaft to vibrate in said working-chambers, a parallel driving-shaft, acrank upon said shaft coupled to one of said pistons, a segmentalsupplychamber intermediate the working-chambers having supply-valves ateachend thereof, a

second rock-shaft mounted parallel with the first in the inner angle ofsaid supply-chamber, a compressing-piston fixed thereon to vibrate inthe supply-chamber, and cranks upon said second rock-shaft anddrivingshaft arranged relatively to each and coupled in manner to causethe compressingpiston to advance toward the working-pistons as they moveinward and recede therefrom as they move outward, substantially in themanner and for the purpose herein set forth.

4. The combination, in a gas-engine, of a central rock-shaft, segmentalworking-chambers formed on opposite sides thereof, oscillating pistonsfixed to the shaft to vibrate in said working-chambers, a paralleldrivingshaft, a crank upon said shaft coupled to one of said pistons, asegmental supply-chamber intermediate the working-chambers and oppositefrom the driving-shaft, a second rockshaft mounted parallel with thefirst in the inner angle of said supply-chamber, a compressing-pistonfixed thereon to vibrate in the supply-chamber, a crank upon said secondrock-shaft arranged relatively to and coupled with a crank upon thedriving-shaft in manner to cause the compressing-piston to advancetoward the working-pistons as they move inward and recede therefrom asthey move outward, valve-controlled ports connecting the two ends of thesupply-chamber with the inner ends of the two working-chambers, and anexhaust-port at the inner end of each working-chamber governed by avalve so actuated by the movements of the secondary crank-shaft as to bepositively opened as the piston begins its inward stroke and positivelyclosed immediately before said stroke is completed, substantially in themanner and for the purpose herein set forth.

5. The combination, with the supply-port for gas and air in agas-engine, and with a cylindrical valve chamber communicating with saidsupply-port, of a tubular valvepiece fitting in said valve-chamber, andwhich is longitudinally divided by a fiat septum into two longitudinalspaces communicating with each other by means of a longitudinal aperturein the septum, one of said spaces being left open peripherally andclosed at its ends by transverse end plates, and the other left open atits ends only to communicate freely with the outer air, said valvepiecehaving also a separate cylindrical bore formed longitudinally in anenlargement of its wall at one angle of the open-ended space, the borebeing closed at one end and made to communicate through an aperture inthe septum with the valve-space whose ends are closed, a gas-supply pipefitted to the open end of the bore, and a valve fitted upon the septumto close down upon the apertures therein, substantially in the mannerand for the purpose herein set forth.

6. The combination, in a gas-engine, with its supply-valve K and withthe gas-inlet In testimony whereof I have signed my IO governed by saidvalve, of the cylindrical name to this specification in the presence ofbore communicating with said inlet, and the two subscribing Witnesses.

perforated movable tube cl, fitted closely in 5 said bore andcommunicating" with a gas- VILLIAM E. CRIST.

' supply pipe, whereby the admission of gas 7 to the inlet-port mayberegulated bya moye- \Vitnesses: ment of said tube, substantially in theman- A. N. JESBERA,

ner and for the purpose herein set forth. E. M. XVATSON.

It is hereby certified that in LettersPatent'No. 417,471, grantedDecember 17 upon the application of William E. Grist, of Brooklyn, NewYork, for an improv in Gas Engines, errors appear in the printedspecification requiring the fol] corrections, viz: In line 25, page 4,a. comma should be inserted after the Word and. the following word"va1veshould read valves; and that the Letters Patent: be read with thesecorrections therein that the same may conform to the record case in thePatent Office.

Signed, countersigned, and sealed this 24th day of December, A. J).1889.

CYRUS BUSSEY, Assistant Secretary of the I'M [snub] Oountersigned G. E.MITCHELL,

Commissioner of Patents.

